Ampco-Pittsburgh is trading 5.01% up at $8.70, with the cause of the October 28 move unconfirmed. - No clear company-specific announcement explaining the move appeared in available news; the company’s releases page lists earlier announcements, including second-quarter results from August. - The U.S. manufacturing PMI reached 56.0 in October, a 53-month high, but that broader data does not establish the reason for the stock’s move. - Major indexes were mixed at midday, offering no clear explanation.